Presentation on theme: "The Liverpool Telescope Chris Davis"— Presentation transcript:
The Liverpool Telescope Chris Davis
Telescope: Ritchey-Chretien; 2.0m primary/0.62m secondary; f/10 at cassegrain Alt-Az mount on hydrostatic bearings; slew rate 2 o /second; Alt range 25 o -87 o Through port clear aperture: 40 arcmin Autoguider: Allows closed-loop tracking (no tip-tilt capability at present) Guider field-of-view: 224 arcsec Can specify cardinal sky angles (0,90,180,270) or specific angle in phase2 GUI. Robotic Control System (RCS): Decides what and how to observe and is responsible for the safe operation of the telescope throughout the night 2 metre Alt-Az 2
Instrumentation IO:O (optical) 4096 x 4112 pixel e2v detector 10' FOV; 12 optical filters IO:I (near-IR) 2048x2048 HgCdTe Hawaii 2RG 6’ FOV; Y,J,H broad band imaging IO:THOR Short exposures (>0.01sec) possible 2’ FoV; “White-light” nm RISE (QUB TRANSIT INSTRUMENT) Short exposures (0.8 sec) 9’ FoV; single fixed “V+R” filter FRODOspec IO:O IO:THOR
Instrumentation Rotating polaroid used to modulate incoming signal 8 images obtained per rotation/every second Currently being used for Blazar and GBR follow- up (Mundell, Steele, et al.)… RINGO3 Fast-readout optical polarimeter 4’ FoV; three broadband beams
Instrumentation Wide-field Skycam-A: All-sky – 4.5 mm fisheye lens; stars down to ~6 th mag Skycam-T: Medium field – 35 mm lens; 21 o field; 73” pixels; down to ~ 12 th mag Skycam-Z: Zoomed – Orion optics AG8 telescope; 1 o field; 3”/pixel; down to ~18 th mag All cameras are Andor ikon-M DU934N-BV No filters; CCD QE from ~ nm Live images (& Movies) available in Quicklook AT
Instrumentation In development SPRAT (Iain Steele & Brian Bolton) Goal – a simple, high-throughput optical spectrometer. Low resolution: R ~ few hundred. Science driver – SN typing 7
Robotic Control System 8 Robotic Control System (RCS) is effectively a robot user that reacts to events as they occur (rise/set of target, changing weather, seeing, sun rise/set, power outages, etc).
Robotic Control System 9 RCS decision-making: The RCS generates a list of Observations that satisfy current constraints. A weighted score is then generated for each observations based on: 1.Proposal science priority (A, B or C). 2.Repeat observations have a higher priority than one-off observations. 3.Urgent observations have a higher priority. 4.Ratio of current elevation vs highest elevation expected that night. 5.Matching of actual (seeing/lunar) conditions to those requested. Calibrations: Standards: o Set to run every 3 hours; sets for photometric and non-photometric. Background standards: o Used for monitoring when there are no science groups available Twilight flats: o Obtained most mornings/evening, as conditions permit.
Science Areas Time Domain and Transient Astronomy Proposals by subject 10 Most proposals are either monitoring of known transients (CVs, Novae, SN, YSOs, etc.) or eclipses (Binaries, Exoplanets, etc.), or Target of Opportunity requests for as-yet unknown events (GRBs, TDEs, etc.).
Science Highlights Thermo-nuclear Super Novae Using Type Ia SN important as a measure of cosmological distances (the redshift-distance relationship) and as probes of Dark Energy. Need high-quality light-curves to characterize low-redshift (z < 0.1) SNe, so can better understand the high-redshift SN used as standard candles. 11 Left: Brighter SNe Ia have wider and bluer light-curves, and are preferentially located in more massive galaxies (Sullivan, Maguire et al.); Right: SN light curve shapes trace the presence of circumstellar material (CSM). Systems with blue-shifted CSM features are ‘wider’; light curve shape may track progenitor type (Maguire et al. 2013).
Science Highlights Gamma-Ray Bursts Dense, photometric monitoring over the first hour (Mundell, Gomboc, et al.) and beyond (Tanvir, Levan, Urkia et al.). Complex profiles include flares that are indicative of central engine activity; need to probe the scale and speed of these events. 12 Above: GRB lightcurves from LT, FT(N) and FT(S) (Melandri et al. 2008). Left: GRB B was a remarkable GRB detected by the Swift satellite on March 19, The burst set a new record for the farthest object that could be seen with the naked eye (z ~ 0.93). It had a peak magnitude of 5.8 and remained visible to the unaided eye for approximately 30 secs. The explosion occurred 7.9 billion years ago. LT data Swift trigger (X-ray) data Other telescopes GRB B Collimated relativistic Fireball model!
Science Highlights Tidal Disruption Events Search for stars tidally- disrupted as they wander too close to a super-massive black hole. Monitoring of SEDs; to determine energy distribution and time evolution. 13 Gezari et al. 2012, Nature 485, 217 Slow Blue Nuclear transients Distant AGN microlensed by stars in foreground galaxies; amplified by factors of 10 – 100 (Lawrence et al.). LT observations triggered by PanSTARRS
Science Highlights RISE Solar-system, Stars and Planets Binary star and planetary transits, occultations, etc. Below: White dwarf CSS eclipsed by M-dwarf companion sec eclipse ingress/egress fully sample in these RISE data such that mid-eclipse time can be measured to within a second. Eclipse time variations (few secs) caused by a circumbinary planet. RISE data (Feb. 2013): Bours et al., U. Warwick. 10 mins 14 Above: Comet ISON - being monitored by professionals and semi-professionals at the LT through imaging, spectroscopy and polarimetry
Other on-going science projects Asteroids and NEOs (Fitzsimmons et al.; Goldaraceno et al.; Vaduvescu et al.) Occultations by Trans-Neptunian Objects (Moreno et al.) Exoplanet detection via microlensing (Horne et al.) X-ray transients and binaries (Monos-Darias et al.; Espinosa et al.) 15 FU Ori and T Tauri outbursts – episodic accretion and outflows (Sigurdsson et al.; Naylor et al.; Davis et al.) Galactic and extra-galactic Novae – short and long period monitoring (Darnley, Bode et al.; Ederoclite et al.) High-z Quasar monitoring (Simpson et al.) LOFAR transients follow-up (Fender, Bersier et al.)
LT strengths… High-impact Science – 36 citations/paper (for papers >3 yrs old) with 14 papers in Nature/Science having on average 86 citations (since ops began in 2004) Broad range of sampling timescales available – From 10 ms to 10 years; monitoring is “actively encouraged”! Optimised scheduling and autonomous rapid follow-up Rapid access to reduced data – Reduced Quick-look within minutes; data reviewed, PI notified and data archived the usually the following day Robotic operations allows for low operating costs – 10.5 staff; £500k/year or £10k/paper Open to collaboration (LOFAR, GAIA, iPTF, etc.) Outreach – National Schools Observatory 5% of telescope time used by NSO 16
LT over the next ~5 years… A stable instrument suite – IO:O and IO:I: Optical and IR imaging/photometry – IO:THOR: rapid optical (lucky) imaging – FRODOspec: IFU optical spectroscopy (R~2500 or 5500) – RINGO3: three-beam Optical Imaging Polarimetry – RISE (exoplanet timing) or SPRAT (R~500 optical spectroscopy) Enhance Rapid-Response capabilities Through improved submission system (eStar-type, template observations waiting on coordinate submission) Nurture collaborations: GAIA and LOFAR transients, iPTF follow-up… Act as a “training ground” for LSST Remain competitive until Operations began in
Liverpool Telescope 2 A replacement facility for Robotic Time Domain Astronomy in 2020 and beyond – Rapid follow up of transient detections from LSST and other facilities – New types of transients: GW, neutrinos, high energy (CTA) – GRB afterglows, (spectroscopy of) SNe on the rise, exoplanets, etc. Capability will build on the strengths of the existing facility – Increased slew rate: GRB observations within tens of seconds? – A greater spectroscopic capability (larger aperture?) – Flexible instrumentation suite; importance of infrared? – LT2 feeding off discoveries made with LT in real time? Science & Technical case for LT2 in development – Community input important: please contact Chris Copperwheat, the LT2 scientist at ARI: or visit the LT2 website at: 18